Recording and/or reproducing device having a take-up reel and having a tape pull-out assembly which can be positioned tangentially with respect to the take-up reel.
The invention relates to a recording and/or reproducing device, into which a cassette can be loaded, which cassette comprises a housing and a rotationally drivable supply reel accommodated in the housing and a record carrier in the form of a tape wound onto the reel hub of the supply reel and a coupling element connected to the record carrier in the area of the free end of the record carrier and held in a coupling position, and which comprises a rotationally drivable take-up reel having a reel hub and a lower reel flange, and which comprises a pull-out element constructed to be coupled to the coupling element, and which comprises retaining means constructed to detachably retain the pull-out element and enabling the pull-out element to be retained in an area in which a coupling to the coupling element can be effected and thereby a pull-out assembly can be formed, which pull-out assembly comprises the pull-out element and the coupling element coupled thereto, and by which retaining means the pull-out element is detachable after its coupling to the coupling element, and which comprises actuating means by which the pull-out assembly can be moved away from the retaining means and up to the reel hub of the take-up reel, in order to bring into engagement with one another, on the one hand, the reel hub and, on the other hand, the pull-out assembly comprising the pull-out element and the coupling element coupled thereto, where with the pull-out assembly brought into engagement with reel hub of the take-up reel a) a partly cylindrical circumferential surface of the reel hub and a partly cylindrical circumferential surface of the pull-out assembly together form a cylindrical winding surface onto which the record carrier in the form of a tape can be wound, and b) the reel hub and the pull-out assembly adjoin one another in the area of a separating zone, and c) the reel hub and the pull-out assembly are positioned with respect to one another in a tangential direction of the reel hub with the aid of tangential positioning means.
Such a recording and/or reproducing device of the type defined in the opening paragraph is known, for example from the patent document WO 98/44499 A1. In the known recording and/or reproducing device the tangential positioning means comprise a positioning wedge which projects from the reel hub of the take-up reel in the area of the separating zone and a positioning recess formed in the pull-out assembly. The positioning wedge is integral with the reel hub of the take-up reel and is made of a plastic. The positioning recess of the pull-out assembly is formed by a recess in the coupling element, which is also made of a plastic. Thus, the tangential positioning means are formed by plastic parts, as a result of which the accuracy of the construction of the tangential positioning means is unsatisfactory because plastic parts can be manufactured only with a limited accuracy, which manifests itself in a limited positioning accuracy in the long run because in particular such a plastic positioning wedge wears out comparatively rapidly and, as a consequence, the positioning accuracy deteriorates as the lifetime becomes longer. Moreover, it has also proved to be unfavorable in the known recording and/or reproducing device that the tangential positioning of the pull-out assembly with respect to the reel hub of the take-up reel by means of the positioning wedge and the positioning recess which cooperates with said wedge is effected not until immediately before the final stage of engagement of the reel hub and the pull-out assembly, during which there may already be such contact between the reel hub and the pull-out assembly that a tangential movement of the pull-out assembly with respect to the reel hub is prevented, which is detrimental to a proper and precise tangential positioning.
It is an object of the invention to preclude the aforementioned problems and to provide an improved recording and/or reproducing device of the type defined in the opening paragraph, in which an accurate tangential positioning of the pull-out assembly with respect to the reel hub of the take-up reel, which is also reproducible over a longer period of life, can be achieved and is guaranteed.
According to the invention, in order to achieve the aforesaid object in a recording and/or reproducing device of the type defined in the opening paragraph, the pull-out assembly has a lower positioning projection which extends in the axial direction of the reel hub of the take-up reel and which projects from the pull-out assembly towards the lower reel flange, and the lower reel flange has a passage for the lower positioning projection, which passage is bounded by two bounding surfaces which extend parallel to the axial direction, and at least one bounding surface of these two bounding surfaces is formed as a lower positioning surface in the area of its end at the hub side, and the lower positioning projection and the lower positioning surface belong to the tangential positioning means.
The measures in accordance with the invention simply enable the use of a positioning projection of a material with which the positioning projection can be manufactured precisely and which also guarantees a low wear over a long period of life, which is advantageous for a high positioning accuracy. Moreover, it is thus achieved that for the positioning projection a material can be chosen which has a high compatibility with the plastic material of which the take-up reel and, consequently, all the positioning surfaces of the tangential positioning means consist. A further advantage of a recording and/or reproducing device in accordance with the invention is that the bounding surfaces of the passage in the lower reel flange of the take-up reel enable a preliminary positioning, which means that a positioning process can already begin when the pull-out assembly is still comparatively far away from its final position on the reel hub of the take-up reel. This possibility of preliminary positioning has also proved to be very advantageous for a maximal accuracy of the final positioning with the aid of the tangential positioning means, as has been corroborated by tests.
In a recording and/or reproducing device it has proved to be particularly advantageous if, in addition, the measures defined in claim 2 are taken, because this enables a particularly high positioning accuracy to be achieved and because this also precludes so-called canting of the pull-out assembly with respect to the reel hub of the take-up reel in a simple manner.
It has proved to be particularly advantageous to provide a cylindrical metal pin as positioning pin because such a metal pin can simply be molded around the pull-out element of the pull-out assembly and because such a metal pin can be manufactured very accurately and is hardly subject to wear.
The above-mentioned as well as further aspects of the invention will become apparent from the embodiments described hereinafter by way of example and will be elucidated with reference to these examples.